Completing missions grants Campaign points for one faction. You can choose which faction’s Campaign you want to progress through, and you can change the selected faction at any time from the Campaign menu.
Among the rewards for progressing through your Campaign, you can receive specific featured cards, Booster Packs, Crystals, Wildcards and random cards for that faction.
Each Campaign node offers a main reward (the one visible from the Campaign Map view) and may contain additional random cards.
The nodes highlighted with a halo contain a premium reward that can be claimed if you own the Premium Campaign for that faction. The Premium Campaign adds an additional layer of rewards that you will unlock as you progress through the faction’s campaign nodes. These rewards are tailored to accelerate completing your deck with additional in-game currency and wildcards - including a Legendary one in the very first node!
Moreover, Premium Campaigns will provide free campaign points for that faction as part of your Login Bonus every day. That means you will be reaping the rewards forever, regardless of which faction you have currently chosen as your selected one, without having to play or meet any criteria other than logging in and collecting them!
If you want to get the most out of your campaigns, upgrade them to Premium Campaigns via the optional purchase found in the Campaign screen.